基于SmartChip HT-qPCR分析不同食品中抗生素抗性基因的多样性及丰度

Diversity and Abundance of Antibiotic Resistance Genes in Various Types of Food Using SmartChip HT-qPCR

摘要:

抗生素抗性基因（Antibiotics Resistance Genes，ARGs）广泛存在于各种环境中，被认为是一种新型环境污染物，对环境及人类健康具有潜在威胁。但是目前对于不同食品中多种ARGs赋存状况的研究仍然有限。该研究采用SmartChip高通量实时定量PCR方法（High-Throughput Quantitative Real-Time PCR，HT-qPCR）对水产品、发酵食品、肉类、蔬菜四大类样品中的ARGs及可移动遗传元件（Mobile Genetic Elements，MGEs）进行了定量分析。结果显示，被分析的15个样品中共检出9个ARGs大类，涉及234个ARGs亚类。所有样品中共有的ARGs亚类为79个，特有的为51个；水产品和肉类样品富集多种ARGs，这些基因表现出较高的丰度（最高可达3.6 copies/16S rRNA gene）。MGEs的检出数量达10个，其中所有样均检出整合子基因intI-1(clinic)和转座酶基因tnpA-01。ARGs抵抗机制分析结果表明，抗生素灭活机制、外排泵机制和细胞保护机制为主要的ARGs抵抗机制，抵抗机制贡献大小依次为：抗生素灭活机制>外排泵机制>细胞保护机制。该研究进一步丰富了对不同食品中ARGs赋存情况的认识，可为食品中ARGs的风险分析提供依据。

Abstract:

Antibiotic resistance genes (ARGs), recognized as emerging environmental contaminants that potentially threaten environments and human health, have been widely identified in various environments. However, the prevalence of ARGs in various types of food is not well understood. In this study, the diversity and abundance of ARGs and mobile genetic elements (MGEs) from four types of food, including aquatic products, fermented food, meat, and vegetables, were quantitatively detected using SmartChip high-throughput quantitative real-time PCR (HT-qPCR). A total of 234 ARG subtypes belonging to 9 ARG types were detected in all 15 samples. Among them, 79 ARG subtypes were common in all samples, and 51 ARG subtypes were detected in specific samples. More ARG types were found in aquatic products and meat (the highest abundance being up to 3.6 copies/16S rRNA gene). Additionally, ten MGEs were detected; among these, integrase gene intI-1(clinic) and transposase gene tnpA-01 were both detected in all samples. The analysis of resistance mechanisms of ARGs suggests that antibiotic deactivation, efflux pump, and cellular protection formed the main resistance mechanisms. The contribution of ARGs to resistance was as follows: antibiotic deactivation > efflux pump > cellular protection. The findings of this study will enhance our understanding of the occurrence of ARGs and MGEs in different types of food and provide important information for an integrative risk assessment of food.